[Tree] Three bugs/problems remaining

Hi everybody,
I'm working on an application based on Ext tree for few weeks. I've almost finish it, but it still remains problems on it.

1) The "tab" key in Firefox

In each branch of my tree i've got many inputs. With IE, when I've got the focus in one of the input, I can use the "tab" key to navigate in the others.In Firefox it doesn't work. When I press tab the focus go outside the tree.

2) Select a value in a drop down reload the page in Firefox
A realy anoying issue with Firefox is about dropdowns. When I click on a value to select it, the page reload itself.
It's bizarre because I havn't any listener on my dropdown.

3) I can't insert "complex" html in each branch with IE

In each branch I insert some html.
Basically, it's a span which contains others span, dropdown, links, etc.
I tried to manualy add the html in the branch (all the html is contained in a variable which I insert), or to did it with "insertHtml" and "append" ext's methods, and the both works fine under Firefox, but not under IE.

If I use the "variable" solution, the content which must be in my main span is outside it.
If I use the ext's methods, I've got this error "Invalide html source code".